海岛棉GbMFT1基因的克隆及表达分析

通过RT-PCR和RACE技术，从新疆海岛棉品种新海14中克隆得到了一个MFT (MOTHER OF FT AND TFL1)类似基因，命名为GbMFT1基因(GenBank登录号为KC513744)。GbMFT1基因的开放阅读框(ORF)为528 bp，编码175个氨基酸的蛋白，含一个磷脂酰乙醇胺结合蛋白(PEBP)结构域。GbMFT1蛋白的羧基端含有MFT蛋白都含有的脯氨酸。系统进化树分析表明GbMFT1编码产物与葡萄、番茄亲缘关系较近，属于同一进化分枝。实时荧光定量PCR分析表明，GbMFT1基因在棉花的不同组织中均有表达，在花瓣中的表达量较高；在纤维发育的不同时期中均有表达，在开花后2 d的胚珠、9 d的纤维中表达量最高。半定量RT-PCR结果表明，GbMFT1基因在刚萌发的种子中表达量高，用不同浓度的ABA处理种子后其表达变化不明显，表明GbMFT1基因的表达不受ABA的调节。

Cloning and Expression Analysis of GbMFT1 Gene in Gossypium barbadense L.

One MFT (MOTHER OF FT AND TFL1)-like homolog was isolated from Gossypium barbadense L. cv. Xinhai14 through RT-PCR and RACE method, which was designated as GbMFT1 gene. The open reading frame (ORF) of GbMFT1 is 528 bp in length, encoding a putative protein of 175 amino acids. GbMFT1 gene has a phosphatidylethanolamin-binding protein (PEBP) conserved motif. Liking almost all MFT-like proteins, GbMFT1 protein has a conserved proline residue near the C-terminus. Phylogenetic analysis revealed that GbMFT1 showed closer kinship with VvMFT and SP2G, indicating that they belong to the same evolutionary branch. Expression analysis by qRT-PCR indicated that GbMFT1 displayed a much broader expression range, with a maximum expression in petal. GbMFT1 was also expressed in different developmental stages of cotton fibres, especially in the two DPA ovules and nine DPA fibres. Expression analysis by semi-quantitative method indicated that GbMFT1 had a high expression level at the begining of seed germination. There existed no significant difference of expression in germinating seeds treated with different concentrations of ABA, indicating the expression of GbMFT1 is not regulated by ABA. Our results lay a good foundation in studying the function of cotton GbMFT1 gene further.